Mating preference inSchistosoma mansoni

We investigated the suitability of an in vitro culture system for measurement of mating behavior ofSchistosoma mansoni. The criteria used to evaluate this system were the level of phosphorylated nucleotides, egg production, and mating status of parasites. The level of ATP, ADP, AMP, and G6-P was measured at different time intervals during cultivation of worm pairs and remained essentially the same as that of control worms for up to 6 days. Egg production was observed in this system during 19 days of cultivation. Peak egg production occurred on day 4 with 72% of the total eggs being laid during the first week of cultivation. The variability in the number of eggs produced by different pairs ofS. mansoni necessitated the selection and matching of tubes with the same number of eggs after 48 hr. This permitted the detection of small changes in egg production by decreasing intertube variation. Mating recognition between male and femaleS. mansoni was evaluated by culturing separated adult worms with their original partner or with a different partner. During the first 24 hr, mating occurred among a greater percentage of worm pairs comprised of their original partner than among worm pairs comprised of different partners (P < 0.001). After 48 and 72 hr of cultivation, these differences were not statistically significant. Similar results were obtained with a culture of mixed males and females. Two drugs were studied for their effects on the mating ofS. mansoni in vitro. Aminoglutethimide (AG) at a concentration of 1 × 10(-4) had no effect on the frequency of mating whereas diethyldithiocarbamate (DDC) completely inhibited mating at a concentration of 3 × 10(-6) M and reduced the level of ATP in these worms.